Some conventional communication systems are known to support wireless and wireline communication between wireless and/or wireline communication devices. Such communication systems range from national and/or international cellular telephone systems to the Internet, and to point-to-point in-home wireless networks. Each type of communication system is designed, and hence operates, in accordance with relevant communication standards. For instance, wireless communication systems may operate in accordance with one or more standards including, but not limited to, IEEE 802.11, Bluetooth, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS), and/or variations thereof.
Depending on the type of wireless communication system, a wireless communication device, for example, a cellular telephone, two-way radio, personal digital assistant (PDA), personal computer (PC), laptop computer, or home entertainment equipment, communicates directly or indirectly with other wireless communication devices. For direct communications, also known as point-to-point communications, the participating wireless communication devices tune their receivers and transmitters to the same channel, or channels, and communicate via those channel(s). Each channel may utilize one or more of the plurality of radio frequency (RF) carriers of the wireless communication system. For indirect wireless communication, each wireless communication device communicates directly with an associated base station, for example, for cellular services, and/or an associated access point, for example, for an in-home or in-building wireless network, via an assigned channel or channels.
In order for each wireless communication device to participate in wireless communication session, it utilizes a built-in radio transceiver, which comprises a receiver and a transmitter, or it is coupled to an associated radio transceiver, for example, a station for in-home and/or in-building wireless communication networks, or a RF modem. The transmitter converts data into RF signals by modulating the data in accordance with the particular wireless communication standard. However, different communication systems may use different standards, for example, the IEEE 802.11 standard and the Bluetooth standard, which may share the same RF spectrum.
In order to alleviate signal interference from sharing an RF spectrum with other communication systems, the Bluetooth standard allows frequency hopping where information is transmitted at various frequencies. In this manner, the energy of the transmitted signal is spread across a RF spectrum from 2.402 GHz to 2.480 GHz in 79 channels with each channel separated by 1 MHz. The Bluetooth standard allows 1600 frequency hops per second. The advantage of the frequency hopping system is that it spreads information across a wide band of frequencies. Therefore, signals transmitted by other systems using a portion of the same frequency spectrum may appear as noise to only some of the frequencies used by Bluetooth in frequency hopping. Similarly, only a portion of Bluetooth transmission may interfere with signals transmitted by other systems.
Two or more Bluetooth devices, up to a total of eight devices, may comprise a piconet with one master device and up to seven slave devices. The piconet may share a common communication data channel with present capacity of 1 megabits per second (Mbps) up to a theoretical maximum of 3 Mbps. This data channel is divided in to time slots of 625 microseconds. Although a master device may initiate contact with any slave device, a slave device may only respond to a master device. A piconet link between a master device and a slave device may be either synchronous connection oriented (SCO) link or asynchronous connectionless (ACL) link. The piconet may support up to three SCO links, and any remaining bandwidth may be utilized by ACL links.
In some current systems, a Bluetooth device may share a platform with a WLAN device, and this may be referred to as coexistence. For example, a device such as a cellular telephone may have integrated thereon a Bluetooth radio and a Wireless LAN radio. There are times when the Bluetooth radio and the WLAN radio may need to operate simultaneously. For example, since the Bluetooth radio and the WLAN radio are close to each other in distance, and both operate in the same frequency band, transmission by one radio may interfere with transmission from the other radio. Transmission by one radio may also interfere with reception on another radio, or reception by the Bluetooth radio and/or the WLAN radio may be interfered with by transmission by other Bluetooth radios and/or WLAN radios.
A coexistence method may be used to communicate when a Bluetooth device is collocated with a WLAN device. Accordingly, the Bluetooth device may signal when the Bluetooth device may be receiving and/or transmitting, and the WLAN device may signal when the WLAN device may be transmitting. The Bluetooth device may indicate whether high priority is desired for subsequent transmissions. The high priority may allow Bluetooth transmission without interference from a simultaneous WLAN transmission. However, the indication typically may need to be made before the start of a frame.
A coexistence method may make use of a packet traffic arbitration (PTA) unit. The PTA unit may receive the priority indications from the WLAN device and the Bluetooth device, and may determine whether the Bluetooth device or the WLAN device may have priority by signaling appropriately to the Bluetooth device and/or the WLAN device. The PTA unit may be located, for example, with the WLAN circuitry. Accordingly, the signaling from the Bluetooth device may be to the WLAN circuitry.
In certain instances, the Bluetooth device may continuously transmit at a high priority, and thereby drastically reduce operating efficiency of the WLAN device. For example, if a HV2 SCO link is established with the Bluetooth device, every other frame may be a high priority frame for the duration of the SCO link. Additionally, if the Bluetooth device also executes a page scan while the SCO link is established, the frames not used for SCO link may be used for a high priority page scan. This may effectively prevent the collocated WLAN device from transmitting until either the SCO link is finished or the page scan is finished.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.